What do you think about this micro cabinet?

[Lebniis]

Wanted to get some input about my cabinet grow I'm starting.

Are two 24 watt T5 Florescent lights from HTG Supply sufficient to get me through flowering. I suppose I'm expecting a little less than a gram per watt, scrog. The cabinet is 2.5'x1.5' by 2' tall.

Any advice of problems that I might run into are encouraged.

Thank you

 

[Diesel_N_Blood]

That looks like great. Probly going to need more light, your looking for 50w's a sqft. With you sqaure footage your going to need at least 100w's. Id double the fluor's or run a 70w hps with t5's to suppliment it. Also turn your scrubber to the top so your pulling air from the top of the cab. Where is the intake. Remember 2x the passive intake to exhuast. Id personally mount the scrubber and fan on the ceiling. Also add a surge protector/powerstrip to the rightside instead of using both plugs. You may want to add something later, (airpumps, cir. fans, etc). I also see no light proofing. If you add 1x1 wood around the whole inside of the cab and then put weather stripping on the 1x1's it should lightproof it.

 

[Lebniis]

Great advice, thanks. Any ideas where affordable t5 are available. 50 bucks from htg is pricey. Not too worried about intake, but maybe I should be if I plan on light proofing it. Im thinking plastic and Velcro. How necessary are 3000k bulbs rather the 6000k vegI have.

 

[FreezerBoy]

Not too worried about intake,

Be afraid. Be very, very afraid.

What you're building is an Easy-Bake oven. You can cook brownies in there (girl scouts are too big.) Seriously, whatever you used to cut the exhaust, use it twice more at the bottom of the cab. Intake=2X exhaust is the easiest, fastest, math free method to cool the cab, exchange the air and control odor.

 

[trem0lo]

Looks really good. You've got the basics covered, one of which is odor control. Install a darkroom louver on one side and you've got a passive intake. This is necessary to keep your temps low. They can be quite big and still maintain negative pressure in the cab. Some weatherstripping should take care of the light leakage.

You could have more light but it's not a necessity. Thumbs up!

 

[Diesel_N_Blood]

Great advice, thanks. Any ideas where affordable t5 are available. 50 bucks from htg is pricey. Not too worried about intake, but maybe I should be if I plan on light proofing it. Im thinking plastic and Velcro. How necessary are 3000k bulbs rather the 6000k vegI have.

First as FB already stated you need to worry about intake. What are you using for a intake now? Looks like you are just relying on the space between the doors to intake air. But with the light proofing that will seal all airflow into your cab. Without proper venting your not grow anything but painfully depressing dreams of plants that will never survive in that torture camber.

Second, the 3000k bulbs would be better for flowering since it has a higher red spectrum which is perfered by flowering plants trying to produce buds. 6000k lights are more suited for veg. growth resembling the mid summer sun. I would use 2:1 ratio of 3k to 6k fluors. that combination can be used from seed to harvest. You could use either for seed to harvest but both would be better.

For a cheap light I'd buy a 150w hps from your local lumber super store. They cost $50 but you tripling you lumen (16,000) output plus the 48w (4000lumen/2000 lumen per lamp) fluorescent that you have

 

[DiscoBiscuit]

You can build your own array with sockets, ballast(s), wire and power cord/plug. A simple wooden frame... length = length of bulbs and width = number of bulbs. You can go with T5 or pl-l type bulbs. Been thinking about making a pl-l array for veg. Holler if you want component info.

Heat rises. The most efficient place to locate the exhaust port is high as possible. Intakes are best at the bottom where air is several degrees cooler.

From the looks of the fan you're not short on horsepower. A rotary speed controller (not a light dimmer) will make less noise. harborfreight.com has em for less than $20. Best wishes, you have a nice start.

 

[Stress_test]

Everything is upside down.

And you will want a small fan inside to move air around or you'll have a mildew farm in there.
I'd also get some kind of a lock mechanism on the doors. It really sucks when somebodies nosy lil kid pulls the doors open in the middle of flower.

 

[Lebniis]

Thank you all very much for the replies. I do not want to cut up the cabinet, so I think I am going to cover the front with a panda plastic velcro door and have a large opening in the plastic. Then the doors will close over the plastic, adjusted to allow maximum air floor around the cracks of the door and eventually into the cab.

My only issue I can't get straightened out is what light to get. I need a low -profile light like the t5 tubes I have now. I'd prefer to not spend more then 80-100 bucks if necessary. What light will maximize the lumens in my cab without heat being an issue. How much heat does a 70 watt and 150 watt hps give off? I'll try to get the best airflow possible but I am a bit worried that I can only do so much.

 

[FreezerBoy]

Then the doors will close over the plastic, adjusted to allow maximum air floor around the cracks of the door and eventually into the cab.

Hope you like your plants well done and blackened. The Easy-Bake oven comment was intended to be funny but, it's no joke. People literally cook food in boxes like that. As in hamburgers go from raw to well done.

Yeah, yeah, IC and it's stupid Laws of Physics. You may not like the Laws of Physics but, they have little sense of humor. Right now the question is: Which comes first? Site wide death, or you getting busted. You're messing with the security of yourself and the plants. The fix is easy. Drill 3 equal sized holes in the cab, one at the top for powered exhaust, two at the bottom for passive intake. 10 minutes work to save you and your plants.

 

[Stress_test]

Hope you like your plants well done and blackened. The Easy-Bake oven comment was intended to be funny but, it's no joke. People literally cook food in boxes like that. As in hamburgers go from raw to well done.

Yeah, yeah, IC and it's stupid Laws of Physics. You may not like the Laws of Physics but, they have little sense of humor. Right now the question is: Which comes first? Site wide death, or you getting busted. You're messing with the security of yourself and the plants. The fix is easy. Drill 3 equal sized holes in the cab, one at the top for powered exhaust, two at the bottom for passive intake. 10 minutes work to save you and your plants.

Couldn't have said it better.

Designing and building a good grow cabinet begins with a calculator and follows a few standard rules to accommodate proper light coverage, fresh air ventilation, internal air movement, heat containment, and ease of access.

To figure out how big of light you should be using, most growers use this formula: Width x Depth = Square Feet 2ft. x 4ft. = 8 sq.ft.
Watts x Square Feet = Desired Wattage 50w x 8sq.ft. = 400 watts
So, we know that a 400 watt grow light would be optimal for the cabinets sq footage. But since it is enclosed heat would detrimental.

Next we calculate the air change ratio required to maintain ambient temperatures. Typically we try for 1 air change per minute, per degree of temperature of heat generated, since lights, ballasts, fans, and even wires radiate heat. Once ambient temperatures are acquired, airflow is adjusted to maintain between 70 - 80 degrees F. depending on humidity and growing style.

Heat is measured in BTU's. The calculation is 3.41 BTU's per watt. Calculate as follows: for a 150W lamp-->> 150W x 3.41 BTU's = 511.5 BTU's.

A BTU is the amount of heat required to increase the temperature of a pint of water (which weighs exactly 16 ounces) by one degree Fahrenheit. Since BTUs are measurements of energy consumption, they can be converted directly to kilowatt-hours (3412 BTUs = 1 kWh) or joules (1 BTU = 1,055.06 joules). A wooden kitchen match produces approximately 1 BTU, and air conditioners for a household use typically produces between 5,000 and 15,000 BTU's.

So 511.5 BTU's is enough heat to raise the temperature of 63.4 gallons of water by 1 degree Fahrenheit.
OR 1 gallon 63.4 degrees.

Your cabinet looks to be approximately 2'D X 4'W X 3'H, which is 24cf. That means that if the cab was filled with water: 24cf X 7.4805 (US gallons per sq ft) = 179.5 gallons X 8 (pints per gallon) = 1436.256 pints divided by 511.5 BTU's = 2.81* F.

So in order to maintain ambient temperatures in your 24 cubic ft cabinet you will need to completely change the air 2.81 times every minute if using a 150 watt light.
A fan speed controller is generally used to fine tune airflow and regulate temperatures and RH.

 

[DiscoBiscuit]

Freezerboy is right, Lebniss. You have a Ferrari for a fan but you'll burn out the bearing prematurely w/o proper air flow.

2x passive intake can be achieved different ways. If your fan has a 4" flange, it's 12.56 square inches. You need to approximate 26 square inches of passive intake. A 9" x 2.75" rectangle would approximate the intake you need.

The cracks in the door aren't enough. You only have 1/8" spacing between the door face and the cab edge. If you multiply 1/8" by the total length of the crack, you only have half the airflow you need. Lay a loose piece of plastic over it and you just blocked that 1/8" crack.

What do I think about this micro cab? You have a great start. You've got enough space for a half pound or more per flip. You have a great fan and scrubber, all you need is the complimentary light for the footprint and you're off to the races.

IMO, your idea for intake is a considerable compromise. Your harvests will only be as good as the weakest element in your environment. Air flow isn't just a way to cool the cab. You only have ~250 ppm of CO2 and air exchange keeps the minimal amount of CO2 replenished.

 

[Lebniis]

Man you guys are really great, I'm having the hardest time cutting into the walls of the cab and am trying to be as least destructive as possible. I guess I am not in a big rush, so I do want to do this right. I can put about a 1/4 inch gap between the cabinet doors and the frame of the cabinet. Then the plastic could be recessed an in or so from the cabinet doors, you guys do not think if the plastic had a 26 square inch hole in it that there would be enough air flow? I mean, I guess you've just told me that.

Uggh, airflow. I'm thinking for lighting I will go with a 2' 4 tube t5 with all bloom bulbs. But man this airflow thing has me stuck.

 

[DiscoBiscuit]

That lamp will generate lots of heat and even a big hole in the plastic would impede air flow. Might even end up with light leaks.

You could put a darkroom vent on the back panel and nobody would know it was there. Even if you convert the cabinet to furniture nobody would know the difference. It's not hard to replace the back panel with a piece of flake board, plywood or masonite if you didn't like the conversion. Hell, some of these cabinets come from the mfg with cardboard or no back panel at all.

I admire your caution, You've got a good start. IMO, your door cracks need to be trapped with felt weather stripping or a bellows (convoluted strip of plastic, etc) along the inside crack.

It would be real easy to convert your exhaust to the top of the back panel. You'd only need one more hole for 2x passive intake. Our you could cut a square large enough around the one hole to mount a darkroom vent.

 

[McGuyver'sDick]

Second the speed controller. That fan seems a little big for that filter. Your in the right place these guys will not steer you wrong.

 

[Stress_test]

Okay here is the thing that somehow always gets lost in the schematics: Flowering requires 12 hours of complete darkness. You can't get any fuckin darkness in the cab if you leave a gap in the doors. Them fuckers gotta be light-tight AND air-tight or you'll grow hermies and everybody within a block will smell your shit.

Stop trying to shortcut things and drill the fuckin holes already. You already cut the hole for the exhaust, just man up and drill the fuckin holes so you can get on with growin some herb sometime when I'm still young enough to appreciate seein the pics.

Damn! Maybe it's just that I'm a guy and have absolutely NO problem drillin holes to please my gals. but it pains me to witness such reluctance to doing it right the first time.

Just imagine the sexy blondes you'll molest in there.

 

[Lebniis]

Stress test: I actually didn't drill the hole for the exhaust. The reason it is where it is because there was a tv outlet that I removed and pushed in the wall. Then with the gapping hole I put the flange and am blowing air into there. Im thinking that ill end up panda plastic the front with no cabinet door and have a 4 or 6 in ducting come in from the front. You all have been super helpful getting me to realize the importance of air flow.

Now does anyone think that a 2 foot 4 bulb sunblaster t5 with all bloom bulbs and the two 6000k t5 I have will be suggicietnt to get dense bugs?

 

[Stress_test]

Stress test: I actually didn't drill the hole for the exhaust. The reason it is where it is because there was a tv outlet that I removed and pushed in the wall. Then with the gapping hole I put the flange and am blowing air into there. Im thinking that ill end up panda plastic the front with no cabinet door and have a 4 or 6 in ducting come in from the front. You all have been super helpful getting me to realize the importance of air flow.

Now does anyone think that a 2 foot 4 bulb sunblaster t5 with all bloom bulbs and the two 6000k t5 I have will be suggicietnt to get dense bugs?

So you're just blowing the exhaust into the wall? I hope that place is a junky rental? Cause a couple of cycles in there will destroy the wall and possibly the ceiling, insulation, and top-plate of that entire wall.

Dude that fan will be blowing warm humid air inside that wall with pretty strong pressure. It will soften the wall sheeting material and blow it off the fuckin framing, and if it's sheet-rock then it won't last thru the first grow.

I think that you still don't understand the dangers of the adventure you are preparing to embark upon...

Growing, even micro growing, is interesting and can be a satisfying hobby, but it is important that you understand just what it is that you are preparing to do.
If you blow the exhaust into a wall, you will destroy that wall. If you destroy the wall, how pissed off is the owner going to be? If it blows the wall off of the other side of the framing, will the neighbors notice?

Your fan and filter are sufficient to allow you to exhaust the air straight into the room and get away with it. But not into a sealed and finished wall.

 

[DiscoBiscuit]

Dense bugs, lol. Let's see, 3.75 sq feet and what, ~200w of light?. That ought to work out. It's gonna be hard to use plastic because venting may contribute to light leaks. The fan could easily suck the plastic into the cab.

In a small room or decent closet, T5 doesn't heat up the show like HPS. But in a small cab with low headroom, you're gonna have the substantial heat of the ballast and the metal fixture very close to the canopy. No worries, your fan is rated to move much more air than your minimum requirement. You just have to find a way to approach ~26" of intake for the fan and block the ambient light from intruding.

Holes in your back panel would be much easier to light trap. You could go to Home Depot and have them cut a piece of 1/4" masonite or 1/4" plywood the same dims as your cab's
back panel. That's your replacement to return the grow cab to normal appearance.

Good luck with everything, hope you enjoy growing your own weed.

EDIT - Hope the tv outlet and 'wall' you're talking about is the cab and not the crib. You can't blow air into walls, studs behind the sheet rock block it. You'd have to go completely through the wall and into another room to get proper air flow.

The fan you have moves a sheet load of air. It's needs approximately 26 sq inches of intake. You'll also need 12.56 square inches to exhaust through.

Your scrubber will take care of the smell. You don't have to vent a 2' T5 into the attic or under the floor. You can exhaust the air into the same room the cab sits. It'll increase your ambient temps no more than 1 or 2 degrees unless you're cab is in a small closet. If that's the case you'll have air flow and temp problems .

 

[Lebniis]

Haha, I mean nugs. Man my ideas are getting beat up that's great. We are on the same page so im listening to all your advice. That's why I posted the thread. So new plan. Exhaust out the front. Hmm maybe ill just put up my 2x4 tent at this point. Was trying to be more stealth and avoid taking up room with my tent